A conventional process control input device as shown in FIG. 1 includes a keyboard K of a digital control computer having a plurality of keys formed on the keyboard, and a track ball T or a mouse M electrically connected with the computer, which may be used for a process control. However, in selecting, changing or manipulating the control details, an operator should depress so many keys on the keyboard or should further operate the track ball or mouse for any control changes or selections, thereby causing an operating inconvenience especially for a complex process control situation.
A conventional analog type process control device is shown in FIG. 2, which requires a very large control panel P for arranging the so many process analog controllers on the panel with each controller provided with a plurality of dedicated push buttons on the controller. If such a conventional control panel is used for controlling a factory having so many areas, the controller buttons will be widely arranged on a very large control panel, which may require more operators for manipulating the controllers with increasing labour and production cost or may cause human response delay for manually pushing buttons for each controller in operating the factory process control especially for treating an emergency operation case to easily cause accident.
It is therefore expected to disclose a simplified unique centralized control rod means for a process control systems operated by plant operators.